Solar cells convert the sun's energy into useful electrical energy by way of the photovoltaic effect. Modern multijunction solar cells operate at efficiencies significantly higher than traditional, silicon solar cells, with the added advantage of being lightweight. Therefore, solar cells provide a reliable, lightweight and sustainable source of electrical energy suitable for a variety of terrestrial and space applications.
During the design and manufacture of solar cells, there is often a need to test solar cells for power generation and overall operating efficiency. One option for testing solar cells is exposing the solar cells to natural sunlight, as if the solar cells were in deployment. However, for a variety of reasons, it is often not practical (or even feasible) to expose test solar cells to natural sunlight.
Thus, solar simulators have been developed as an alternative to testing solar cells with natural sunlight. Advantageously, solar simulators facilitate the indoor testing of solar cells under controlled laboratory conditions.
Unfortunately, many traditional solar simulators produce a limited area of illumination and, therefore, are not suitable for testing large solar cells and solar cell arrays. Furthermore, while the illumination produced by traditional solar simulators may resemble the spectral distribution of natural sunlight, there are often discrepancies in the spectral distribution and the spatial uniformity of the generated illumination that may compromise test results. Solar simulators having a more precise spectral distribution and greater spatial uniformity typically are large, must be operated continuously, and have a relatively short lamp life.
Accordingly, those skilled in the art continue with research and development efforts in the field of artificial solar illumination.